How To Keep Nitrates Down?

Note: When a new tank is filled for the first time, the water needs to be completely cycled before adding fish. This section assumes that your aquarium cycling has already been well established, and your aquarium stocked. Continue reading article below to gain some valuable insight!

What are Nitrates?

Nitrates are part of nature in the ocean, and likewise, in aquariums. As waste breaks down in the water, it cycles from ammonia to nitrite to nitrates. The first two are highly toxic to marine life, so it is important to test aquarium water regularly, to make sure it tests zero for these.

Nitrates, on the other hand, aren't completely bad. Few organisms require nitrates, but small levels are beneficial to some. Both micro and macro algae love the stuff, while fish only tolerate it. Invertebrates suffer from it, if the levels are too high. However, studies have shown that a little is required to keep clams happy. In order for aquarium water to match nature's sea water as closely as possible, nitrates must be kept down to no more than 10-20 ppm (parts per million).

Is your aquarium suffering from high nitrate levels?

First things first: If your aquarium begins suffering from high nitrate levels the continued success of your reef will depend on you being able to determine the cause, and getting them under control. Some possible causes are: an accumulation of matter on filter media such as bio balls, biowheels, filter pads, foam blocks, and underground gravel filters. Other causes of high nitrates include decaying matter, overfeeding, or a lack of water changes and regular maintenance.

Nitrates are in the water column, not your substrate or rockwork. Changing the majority of the tank water might seem ideal, but it may shock your corals, fish and invertebrates in the process. Therefore, smaller and more frequent water changes are recommended.

Adding filtering equipment, such as an aquarium sump or refugium, are highly recommended to control nitrates, especially for Reef tanks over 30 gallons.

Adding phosphate absorbing media and nitrate absorbent media (e.g. adding the media to a sock) inside the sump filtration, will also quickly and efficiently help reduce nitrates. If adding a refugium, placing macro algae in it, along with a small sandbed, will also help denitrify the tank. Once the high levels of nitrates have been brought down to normal, your regular maintenance routine along with a monthly or bi-monthly water change is all that will be needed.

Along with proper feeding, proper care techniques, and regular maintenance, your nitrate problems will be minimized, your aquarium will be healthier and happier, and you will enjoy your hobby even more.